When white light passes through a hollow prism, then

Question

Question

This question was previously asked in

ALP CBT 2 Physics and Maths Previous Paper 3 (Held On: 21 Jan 2019 Shift 3)

Answer 1

CONCEPT:

Dispersion of light: The phenomenon in which a white light ray when falls on a prism get separated into its component colors is called dispersion of light.

When light rays fall on the prism then there is a deviation in the path of the ray after refraction through the prism.

EXPLANATION:

When the light rays enter the first wall of the hollow prism then it bends towards normal to the surface because it enters the denser medium.
Just the opposite will happen when it leaves the first wall and the ray will bend away from normal because it enters a lighter medium with exactly the same angle.
Similarly, when the light ray enters the wall on the other side, on the way towards the exit, it bends toward normal.
And finally bends away from the normal at the exit.
Thus we find that there is no dispersion and no deviation of light rays. So option 3 is correct.